Table 4.
SSE between predicted (by iMAC868) and observed growth yields for acetate- and methanol-grown cells at different ratios of Na+ and H+ exchange by Mrp antiporter and varying ratios of Na+ and H+ uptake by ATP synthase
| Substrate | Ratio of Na+ to H+ exchange by Mrp antiporter | Ratio of Na+ to H+ uptake by ATP synthase | ||||
|---|---|---|---|---|---|---|
| 3:1 | 1:1 | 1:3 | 2:1 | 1:2 | ||
| Methanol | 3:1 | 2.11E−04 | 7.75E−06 | 2.21E−04 | 1.75E−02 | 2.53E−05 |
| 2:1 | 1.40E−07 | 8.58E−05 | 2.86E−04 | 1.67E−04 | 1.40E−07 | |
| 1:1 | 4.57E−04 | 4.57E−04 | 4.57E−04 | 8.33E−05 | 8.33E−05 | |
| 1:2 | 1.39E−03 | 6.73E−04 | 1.43E−04 | 1.43E−04 | 3.32E−05 | |
| 1:3 | 1.57E−03 | 5.44E−04 | 1.26E−06 | 1.73E−04 | 1.78E−04 | |
| Acetate | 3:1 | 7.97E−06 | 2.13E−04 | Infeasible | 3.93E−02 | 4.76E−05 |
| 2:1 | 8.00E−06 | 7.34E−05 | 2.96E−04 | 3.44E−04 | 8.00E−06 | |
| 1:1 | 8.05E−06 | 8.05E−06 | 8.05E−06 | 5.51E−04 | 5.51E−04 | |
| 1:2 | 8.09E−06 | 1.82E−04 | 7.45E−04 | 7.45E−04 | 2.10E−03 | |
| 1:3 | 8.10E−06 | 3.45E−04 | 1.74E−03 | 8.36E−04 | 3.34E−03 | |
Only the 2:1 ratio of Na+ and H+ for Mrp satisfies the closest match between predicted and observed growth yields for both substrates. ATP synthase can uptake either 3 Na+ and 1 H+ (bold italics) or 1 Na+ and 2 H+ (italics), which are rendered equivalent by Mrp. Infeasibility arises from the inability to meet minimum ATP requirements